Sony UP-890MD - 5-5. Motor Drive Section (IC201)

5-5. MOTOR DRIVE SECTION (1C201)
The
platen
motor,
Head
UP/down
motor,
and
Door
motor
are
driven
with
IC201,
1C202,
IC203,
and
I1C204,.
They
are
all
controlled
by
IC301.
5-5-1. Platen motor
The platen motor speed is controlled by IC201(M51970L). The frequency of the FG
(optic
read
out)
of
the
motor
section
is
detected
and
fed
back
to
IC201,
which
controls motor drive transistor Q205 to control the speed.
10204 (M54544AL) can drive the motor in the forward or reverse direction.
The motor is turned ON/OFF and its speed controlled by 1C301-@ ,@,@,@.
(See the explanation of the system control section.)
Since this unit produces the INT-V signal that provides the screen printing timing
by dividing the FG frequency, even if there is some slight fluctuation in the FG
frequency, the paper feed distance and printing quality are held constant.
5-5-2. Head U/D motor and DOOR motor
The Head U/D motor and DOOR motor are controlled by IC202 and 203 (both
are M54543L). This IC can drive the motor in the forward or reverse direction, and
it is controlled by 1C301-@,@,@,@.
Head U/D motor
[rere ies [open
goes down the head
goes up the head
locks to motor
Door motor
iam o- -_
OPEN Opens the door
CLOSE Closes the door
The above motor operation is controlled by detecting the condition of Head and
Door with 1C301 Pin@),@,@,@.
Head condition
oo
L L
H L
L H
Door condition
ee oo
Open L H The door is opened.
Close H L The door is closed.
Top position of the
head to open the door.
Head is at this position
except for [PRINT|
Head is pressed
Top
Middle
against the platen.